Rapid Thermal Oxide passivation using IC-grade processing

We report on Rapid Thermal Oxide (RTO) passivation films grown on both n- and p-type wafers using 300 mm IC tools, in order to determine state-of-the-art passivation performance with wafer-based silicon solar cell applications in mind. Films in the range of 1.2 to 15 nm were grown using Applied Materials' RadOx® process, a proprietary method employing hydrogen and oxygen radicals to enhance growth rate. Surface recombination velocities (SRVs) better than 30 cm/sec are reported for both substrate types. The 5 nm layers show the lowest SRV. These layers require process times on the order of 20 seconds. The results suggest that proper tool and process design may enable in-line oxide passivation with quality consistent with furnace-based systems and throughput consistent with high-volume solar cell manufacturing requirements.